What is the directrix (x-2)^2=8(y-1) ?

The directrix (x-2)^2=8(y-1) is y=-1

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

directrix (x-2)^2=8(y-1)

directrix

(x - 2)^{2} = 8 (y - 1)

y = - 1

Solution steps

Rewrite

(x - 2)^{2} = 8 (y - 1)

in the standard form:

4 \cdot 2 (y - 1) = (x - 2)^{2}

(h, k) = (2, 1), p = 2

Parabola is symmetric around the y-axis and so the directrix is a line parallel to the x-axis, a distance

- p

from the center

(2, 1)

y-coordinate

y = 1 - p

y = 1 - 2

Refine

y = - 1

- x^{2} + 6 x - 9

(x + 3)^{2} = 24 (y - 1)

x^{2} + 2 x + 1

x^{2} - 20 x + 100

y = 2 x^{2} + 4